--- a/src/hotspot/share/oops/klass.hpp	Mon Nov 20 12:04:13 2017 +0100
+++ b/src/hotspot/share/oops/klass.hpp	Mon Nov 20 13:07:44 2017 +0100
@@ -408,6 +408,11 @@
       return search_secondary_supers(k);
     }
   }
+
+  // Is an oop/narrowOop null or subtype of this Klass?
+  template <typename T>
+  bool is_instanceof_or_null(T element);
+
   bool search_secondary_supers(Klass* k) const;
 
   // Find LCA in class hierarchy